Risk, Helmets, and Skiing Injuries

Tomorrow’s NatPost column is on a recent BMJ study concerning helmet use among skiers & snowboarders, and the current illogical penchant among such folks for wearing protective headgear. I argue it is partly a societal misunderstanding of risks and injury incidence, and partly some typically emotional behavior by skiers themselves.

Here is the column:

It has been almost three years since I last went on a ski trip. I just got back from a week skiing, and things have changed enough to make the experience nearly unrecognizable.

Changes are also taking place closer to the ground, with old-style skis being replaced by more curvaceous creations. The new Ana Nicole Smith-style skis are voluptuous and shapely; they are tail-waggingly eager to go s-turning through bumps and steeps, courtesy of a narrow waist and wide bosom that together convert momentum into sinusoidal tracks. Skiers who, until now, could not carve turns, can now arc down trails better than they can snowplow.

New ski technologies also mean that skiers who used to avoid tough terrain can slide blithely onto 40-degree slopes, sans the stomach-emptying nervousness of a decade ago. Where old skis had to be exhaustingly hopped from turn to turn on the steeps, new skis zip from edge-to-edge so easily that the toughest slopes can be handled by people with average skill.

This change has, of course, unintended consequences, including that skiers are much more likely to find themselves adrift in risky territory. What can or should be done about it? Nothing, of course. People are going to test limits, and warning them about risks wonâ€™t change much â€“ nor will the current vogue for helmets, despite a recently-released study that argues for more such usage.

The study, published recently in the British Medical Journal, found that skiers and snowboarders can reduce the risk of head injury in an accident by almost a third by wearing a helmet. Given the studyâ€™s reliance on data from more than 4,300 accidents at 19 major ski areas in Quebec during the winter of 2001-02, there is little point in disagreeing with its conclusion. After all, unless youâ€™re going to argue that either Quebec skiers, or the winter of 2001-02, are somehow anomalous, then youâ€™re stuck with recognizing that helmets make skiing safer.

But you have to put it in context: What is the incidence of skiing injuries? After all, if the helmet-less rate of skiing-related head injury is 1 for ever 1000 skier-days then that is one thing, but if the rate is 1 for every ten then that is something else altogether.

Estimates vary, but the consensus from other studies is that the rate of skiing injuries is something like 2 to 3 per 1000 skier-days. The most frequent injury is knee-related, followed by arm and then lower leg. The incidence rate of head injuries is lower yet, on the order of one every 3000 skier-days. In other words, the average skier is likely to be prevented from getting a head injury by having torn their ACL and then broken their arm, thus taking them off the slope entirely.

So who do so many skiers wear helmets, and why do so many safety sorts want the rest of us toque-wearers to don domes? It is a typical mixture of things, including a nanny-society overreaction, with safety mavens looking to make us all safer, even if we werenâ€™t in danger in the first place.

But skiers are to blame too, in their screwy illogic. People recognize, at least implicitly, that they canâ€™t do much to make themselves safe from (common) knee injuries while skiing, but they can protect themselves from (uncommon) head injuries — so they wear helmets and risk their knees.

In other words, skiers wearing helmets are a little like drunks losing their keys in a dark alley, and then looking for the shiny things under a bright lamppost. It may not make sense, but it sure is easier.

I think there is something that needs explaining.
You claim that ACL injuries and broken arms prevent many head injuries by taking skiers off the slopes. Is it your claim that head injuries occur in skiers that already have ACL injuries and broken bones?
Professor, I think you need to revisit either basic statistics texts or basic logic texts…

I am a devoted fan but must disagree with you on this one. about 10 years ago, when one of Toronto’s best architects fell at Osler and had a serious concussion, I tried to design a helmet that looked like a toque and would protect people from the most common accidents- the headbanger concussion that you get in Ontario from skiing or boarding on ice. I spent 5 years on this project that died because conventional (and overdesigned) helmets are now acceptable on the slopes.
Forget the trees and the spectacular crashes- concussions happen all of the time and are completely underrated in terms of their effect on you. On a snowboard it is easier to hit your head than on skiis; in Ontario you are invariably falling on groomed icy surfaces.
A doctor said to me ” you would not carry an expensive laptop around without a case or protection, yet you are willing to do it with your brain”
lets not talk about saving lives and kennedys and sonny bonos- lets talk about banging your head and having it rattle about for months or years or forever. Concussions change you. Helmets turn what could be major events into spills that do not get listed or registered by anyone on a ski patrol.

Perhaps I’ve overlooked it, but don’t you have to have some estimate of the cost of helmet wearing (or at least the sign of the cost!) before you can do this analysis? If helmets are cool, the cost of wearing one may be small, or even negative, in which case it’s entirely rational (“rational”) to wear one even if it’s incredibly unlikely to prevent an injury.
Just a thought… *8)